Conventional communication systems include multiple network elements such as entities, nodes, and gateways that implement different sets of functions to support wireless communication. For example, the evolved packet core (EPC) network defined by the Third Generation Partnership Project (3GPP) includes a mobility management entity (MME) to implement functions including authentication and mobility management, a serving gateway (SGW) to implement functions including lawful intercept and providing a mobility anchor for user equipment, a packet data node (PDN) gateway (PGW) to implement functions including charging and policy/rate enforcement, and an authentication, authorization, and accounting (AAA) entity to implement functions including authentication and charging. For another example, a general packet radio service (GPRS) network includes nodes such as a gateway GPRS support node (GGSN) to implement functions including packet routing and forwarding and a serving GPRS support node (SGSN) to implement functions including packet routing, mobility management, authentication, and charging. Interfaces between the functions implemented in the network elements are referred to as reference points, which have defined sets of capabilities and protocols. Each network element supports multiple interfaces to multiple other network elements. For example, an SGW in an EPC network supports an interface to an MME, interfaces to one or more PGWs that are connected to corresponding external networks, and one or more interfaces to base stations or eNodeBs in the communication system. The network element can also support interfaces to an SGSN for 3G interworking and to a PCRF for non-3GPP access policy control.